package com.share.util;

import java.io.*;

import org.springframework.web.multipart.MultipartFile;

import sun.misc.BASE64Decoder;

/**
 * 用来吧Base64的字符串转换成MultiparFile对象
 *
 * @author 博博
 * @Title: BASE64DecodedMultipartFile
 * @ProjectName SharedLibrary
 * @time 2018/12/18 15:41
 */
public class BASE64DecodedMultipartFile implements MultipartFile {
	private final byte[] imgContent;
	private final String header;

	public BASE64DecodedMultipartFile(byte[] imgContent, String header) {
		this.imgContent = imgContent;
		this.header = header.split(";")[0];
	}

	@Override
	public String getName() {
		// TODO - implementation depends on your requirements
		return System.currentTimeMillis() + Math.random() + "."
				+ header.split("/")[1];
	}

	@Override
	public String getOriginalFilename() {
		// TODO - implementation depends on your requirements
		return System.currentTimeMillis() + (int) Math.random() * 10000 + "."
				+ header.split("/")[1];
	}

	@Override
	public String getContentType() {
		// TODO - implementation depends on your requirements
		return header.split(":")[1];
	}

	@Override
	public boolean isEmpty() {
		return imgContent == null || imgContent.length == 0;
	}

	@Override
	public long getSize() {
		return imgContent.length;
	}

	@Override
	public byte[] getBytes() throws IOException {
		return imgContent;
	}

	@Override
	public InputStream getInputStream() throws IOException {
		return new ByteArrayInputStream(imgContent);
	}

	@Override
	public void transferTo(File dest)
			throws IOException, IllegalStateException {
		new FileOutputStream(dest).write(imgContent);
	}

	public static MultipartFile base64ToMultipart(String base64) {
		try {
			String[] baseStrs = base64.split(",");

			BASE64Decoder decoder = new BASE64Decoder();
			byte[] b = new byte[0];
			b = decoder.decodeBuffer(baseStrs[1]);

			for (int i = 0; i < b.length; ++i) {
				if (b[i] < 0) {
					b[i] += 256;
				}
			}

			return new BASE64DecodedMultipartFile(b, baseStrs[0]);
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}
}
